CppunitTest_sw_htmlexport failing due to zlib variation?

[Stephan Bergmann]

On 26/08/2020 08:37, Stephan Bergmann wrote:
> On 25/08/2020 11:07, Stephan Bergmann wrote:
>> At least when building recent master on recent Fedora rawhide aarch64 
>> with (among others) --with-system-zlib, CppunitTest_sw_htmlexport 
>> fails with
> [...]
>> The base64-encoded payload apparently is a PNG image.  And from what 
>> little I know about PNG, it looks plausible to me that there can be 
>> different (compressed) PNG content that decompress to identical raw 
>> data, and that the LibreOffice code would be allowed to generate 
>> differing (compressed) PNG content for the above data:image/png URL 
>> payload.
> 
> What supports the theory that "the LibreOffice code would be allowed to 
> generate differing (compressed) PNG content" is the Fedora zlib commit 
> <https://src.fedoraproject.org/rpms/zlib/c/25e9802713484882c27c1f979a6610a42414ee13> 
> "aarch64 optimizations", adding lots of code that presumably is only 
> relevant for aarch64 and presumably changes details of the compression 
> algorithm.

...and looks like 
<https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/message/AMOZA4K5RKCZEKA6QWY4PLM34UH3ZZ4Q/> 
"Re: Fwd: Re: CppunitTest_sw_htmlexport failing due to zlib variation?" 
on the Fedora dev list supports the theory even further